Nuclear power that was once advertised as being “too cheap to meter” has evidently become too costly for electric utilities to buy. Apart from two 1,000 megawatt reactors being constructed in Georgia at enormous expense to ratepayers (even after subsidies from tax payers), there are no immediate prospects for new nuclear power plants in the United States. What of the longer-term future?

One possibility for new nuclear reactor construction comes from what are called the Small Modular Reactors (SMRs). One SMR design called NuScale is slowly making its way to potential construction. Developed by a company based in Oregon, a single NuScale reactor is designed to generate just 50 megawatts of power.Earlier this spring, the NuScale design cleared the first phase of the Nuclear Regulatory Commission’s certification process. A group of electrical utilities called the Utah Associated Municipal Power Systems has expressed an interest in purchasing a power plant, which consists of 12 NuScale reactors. The Tennessee Valley Authority also has applied for a permit to develop a site that could host an SMR.

Why SMRs? According to promoters of these scaled-down reactors, they could solve the multiple challenges faced by nuclear power. SMR developers promise lowered costs, decreased production of radioactive waste, reduction or even elimination of the risk of severe accidents, and no contribution to nuclear proliferation. Dozens of companies claim to be developing their own SMR designs, and many have received funding from wealthy private investors and the U.S. Department of Energy.

However, there is little to suggest SMRs will somehow magically remedy all that ails the nuclear industry. SMRs, as the name suggests, produce relatively small amounts of electricity in comparison with currently operational reactors. This puts them at a disadvantage.

One known way to reduce the cost of nuclear electricity has been to build larger reactors because the expenses associated with constructing and operating a reactor do not increase in direct proportion to the power generated. SMRs will, therefore, cost more than large reactors for each unit of generation capacity. Most of the small reactors built in the United States shut down early because they couldn’t compete economically.

SMR proponents argue that they can compensate by savings through mass manufacture in factories and learning how to hold down costs from the experience of constructing lots of reactors. This is a dubious assumption: In both the United States and France, the two countries with the highest numbers of nuclear plants, costs went up, not down, with construction experience.

Even if one were to assume that such “learning” actually occurs, SMRs have to be manufactured by the thousands to achieve meaningful savings. There is simply no market for so many reactors.

Even Westinghouse, the company that has directly or indirectly designed the majority of the world’s nuclear reactors, has realized that there is no market. For a decade or more, Westinghouse pursued a SMR design. But, in 2014, the company abandoned that effort. Its CEO explained: “The problem I have with SMRs is not the technology, it’s not the deployment — it’s that there’s no customers.” Few or no customers means no one would, or should, want to build a factory to construct the modules constituting these SMRs.

For example, safety can be improved by making reactors smaller. But, a smaller reactor, at least the water-cooled reactors that are most likely to be built earliest, will produce more, not less, nuclear waste per unit of electricity they generate because of lower efficiencies. With no long-term solution in sight for nuclear waste, accumulating more radioactive spent fuel aggravates the storage problem.

The poor economic outlook for SMRs also affects safety. Companies that market SMRs propose placing multiple reactors in close proximity to save on costs of associated infrastructure. But this would increase the risk of accidents or the impact of potential accidents on the surrounding population.

At Japan’s Fukushima nuclear complex, explosions at one reactor damaged the spent fuel pool in a co-located reactor. Radiation leaks from one unit made it difficult for emergency workers to approach the other units.

The future of nuclear power in the United States, and indeed in much of the world, is bleak. Small modular reactors will not change that prognosis. There is no point in wasting public money on promoting them.

M. V. Ramana is the Simons chairman in Disarmament, Global and Human Security at the School of Public Policy and Global Affairs, University of British Columbia and the author of “The Power of Promise: Examining Nuclear Energyin India.”